Mathematics to Chemistry, 



271 



atoms hydrogen and one oxygen, and deutoxide of hydrogen 

 consists of one of each; hence, 16 is the atomic weight of 

 oxygen. 



The same sentence will nearly apply to the following 

 couple of compounds, viz., sulphuretted hydrogen and bi- 

 sulphuretted hydrogen : these then must agree in com- 

 position with one of the former couples, which confirms the 

 conclusion. Many similar compounds exist and testify the 

 same thing. One additional instance will be abundantly 

 sufficient, taken from carbonic and nitric oxides. 



1 . A volume of carbonic oxide is double that of its 

 oxygen, and combined with another volume of oxygen, it 

 becomes carbonic acid, without change of volume. 



2. A volume of nitric acid is double that of its nitrogen, 

 and combined with another volume of nitrogen it becomes 

 nitrous oxide, without change of volume. 



It follows from these analogies, that the substances 

 before us are composed after the same manner : now, accord- 

 ing to both views, carbonic oxide is one atom oxygen and 

 one carbon ; hence, nitric oxide is one nitrogen and one 

 oxygen ; but by weight the constituents are in the ratio of 

 14 to 16, and 14 is the atomic weight of nitrogen, therefore, 

 16 is that of oxygen. 



The other atomic weights used in this paper are taken 

 from Dr. Thomson's determinations, doubling some of them 

 on account of using 16 for oxygen. They are inserted in 

 the following table, and the numbers of Berzelius are 

 annexed ; the substances in italics are double the numbers 

 given by Dr. Thomson. 



